gh-85795: Raise a clear error when super() is used in typing.NamedTuple subclasses (#130082)

bswck · web-flow · commit 293fa3433e40 · 2025-03-05T20:45:47.000-08:00
diff --git a/Doc/library/typing.rst b/Doc/library/typing.rst
@@ -2398,6 +2398,10 @@ types.
    .. versionchanged:: 3.11
       Added support for generic namedtuples.
 
+   .. versionchanged:: next
+      Using :func:`super` (and the ``__class__`` :term:`closure variable`) in methods of ``NamedTuple`` subclasses
+      is unsupported and causes a :class:`TypeError`.
+
    .. deprecated-removed:: 3.13 3.15
       The undocumented keyword argument syntax for creating NamedTuple classes
       (``NT = NamedTuple("NT", x=int)``) is deprecated, and will be disallowed
diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
@@ -8349,6 +8349,23 @@ class VeryAnnoying(metaclass=Meta): pass
             class Foo(NamedTuple):
                 attr = very_annoying
 
+    def test_super_explicitly_disallowed(self):
+        expected_message = (
+            "uses of super() and __class__ are unsupported "
+            "in methods of NamedTuple subclasses"
+        )
+
+        with self.assertRaises(TypeError, msg=expected_message):
+            class ThisWontWork(NamedTuple):
+                def __repr__(self):
+                    return super().__repr__()
+
+        with self.assertRaises(TypeError, msg=expected_message):
+            class ThisWontWorkEither(NamedTuple):
+                @property
+                def name(self):
+                    return __class__.__name__
+
 
 class TypedDictTests(BaseTestCase):
     def test_basics_functional_syntax(self):
diff --git a/Lib/typing.py b/Lib/typing.py
@@ -2889,6 +2889,9 @@ def annotate(format):
 class NamedTupleMeta(type):
     def __new__(cls, typename, bases, ns):
         assert _NamedTuple in bases
+        if "__classcell__" in ns:
+            raise TypeError(
+                "uses of super() and __class__ are unsupported in methods of NamedTuple subclasses")
         for base in bases:
             if base is not _NamedTuple and base is not Generic:
                 raise TypeError(
diff --git a/Misc/NEWS.d/next/Library/2025-02-13-15-10-56.gh-issue-85795.jeXXI9.rst b/Misc/NEWS.d/next/Library/2025-02-13-15-10-56.gh-issue-85795.jeXXI9.rst
@@ -0,0 +1,3 @@
+Using :func:`super` and ``__class__`` :term:`closure variable` in
+user-defined methods of :class:`typing.NamedTuple` subclasses is now
+explicitly prohibited at runtime. Contributed by Bartosz Sławecki in :gh:`130082`.

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1,3 @@`
	`1`	+Using :func:`super` and ``__class__`` :term:`closure variable` in
	`2`	+user-defined methods of :class:`typing.NamedTuple` subclasses is now
	`3`	+explicitly prohibited at runtime. Contributed by Bartosz Sławecki in :gh:`130082`.